FIELD OF THE INVENTION
[0001] The invention relates to a lighting device comprising (a) a light source configured
to generate light source light, and (b) a light converter configured to convert at
least part of the light source light into visible converter light. The invention further
pertains to such light converter per as well as to an organic luminescent material
that can comprised by such light converter.
BACKGROUND OF THE INVENTION
[0002] Phosphor-enhanced light sources are known per se and are used for substantially all
kinds of light sources. Phosphor-enhanced light sources comprise a light emitter and
a luminescent material. The luminescent material is arranged for converting at least
part of the light emitted by the light emitter into light of a longer wavelength.
[0003] Well-known phosphor-enhanced light sources are, for example, mercury vapor discharge
lamps in which the light is emitted from a discharge in which the presence of mercury
vapor causes the discharge to emit ultraviolet radiation. At least a part of the ultraviolet
radiation is absorbed by a luminescent material and converted into light of a longer
wavelength which is subsequently emitted by the luminescent material. Such mercury
vapor discharge lamp may, for example, comprise a discharge vessel in which the discharge
is generated. The luminescent material is typically applied to the inner wall of the
discharge vessel such that the ultraviolet radiation emitted by the discharge does
not need to pass the discharge vessel but is inside the discharge vessel converted
into, for example, visible light.
[0004] Alternatively, the phosphor-enhanced light source may comprise a solid-state light
emitter as the light emitter. Such a solid-state light emitter may, for example, be
a light emitting diode, or a laser diode, or an organic light emitting diode. The
light emitted by a solid-state light emitter typically has a relatively narrow spectrum
arranged around a center wavelength. The width of the spectrum may, for example, be
defined by the Full Width Half Maximum (further also indicated as FWHM) of the emission
peak which is a width of the emission peak measured at an intensity being half the
maximum emission intensity of the light emitted by the solid-state light emitter.
The FWHM of a typical emission spectrum of the solid-state light emitter is less than
30 nanometer, which is typically identified by the human eye as light of a single
color.
[0005] To change the color of the light emitted by the solid- state light emitter, luminescent
materials may be added to generate a phosphor-enhanced light source. The luminescent
material may, for example, be applied as a layer on top of the (LED) die of the solid-state
light emitter, or may, for example, be dispersed in a matrix which may be located
at a distance of the solid-state light emitter, a so called "remote phosphor" arrangement.
The luminescent material may also be part of a mixture of different luminescent materials,
for example, each generating a different color such that the mixed light, for example,
generates white light having a specific color temperature. Furthermore, luminescent
materials may be added to solid-state light emitters to improve the color rendering
characteristics of the solid-state light emitters, as the typical emission characteristic
of the luminescent materials is a relatively broad spectrum of light.
[0006] The use of dyes in matrices is (also) known in the art.
US6537679, for instance, describes a fluorescent retro reflective article comprising a polymer
resin comprising poly(1,4-cyclohexanedimethanol-co-ethylene terephthalate)(PETG) and
a fluorescent dye selected from the group consisting of perylene imide and perylene
ester dyes, thioxanthene dyes, benzoxanthene dyes, and benzothiazine dyes. The PETG
fluorescent resin matrix can be used to enhance daytime visibility of a roadway marker.
Such a pavement marker comprises a base member comprising a structure of a light-transmissible
fluorescent material, the structure having a top surface and a front edge surface,
the base member being configured to provide an air cap beneath the structure.
[0007] FR2089620 describes a material indicated with the following general formula:

wherein X represents 0 or an N-R group, and wherein Y represent 0 or S.
[0008] WO2012140542 describes a luminescent converter, a phosphor-enhanced light source and a luminaire
are provided. The luminescent converter comprises a first organic luminescent material,
a second organic luminescent material and a third inorganic luminescent material.
The first organic luminescent material, the second organic luminescent material and
the inorganic luminescent material absorb a portion of light emitted by the light
source and/or absorbs a portion of light emitted by at least one of the other luminescent
materials. The first organic luminescent material converts at least a part of the
absorbed light into light of a first color distribution. The second organic luminescent
material converts at least a part of the absorbed light into light of a second color
distribution. The inorganic luminescent material converts at least a part of the absorbed
light into a third color distribution to compensate self-absorption of light by at
least one of the first organic luminescent material and the second organic luminescent
material.
[0009] WO02055570 describes a fluorescent article in which a UV light screening layer comprising a
polymer having in its backbone repeating units of a UV light absorbing moiety, or
a moiety capable of being transformed by Photo-Fries rearrangement into a UV light
absorbing moiety, is disposed in operative screening relation to a layer containing
a fluorescent colorant. The UV light screening layer affords surprisingly improved
fluorescence protection as compared to prior UV light screening layers having only
UV light absorbing additives.
SUMMARY OF THE INVENTION
[0010] Efficiency of white emitting light solid state light sources can still be improved.
This can be best done by combining RGB LEDs. However, green LEDs are presently not
efficient enough in order to obtain high efficiencies. For this reason, phosphor converted
(PC) LEDs are suggested for obtaining white light. With the blue LED's as primary
source a red and yellow luminescent phosphors are needed. These phosphors should be
stable under blue light irradiation conditions during the lifetime of the complete
light source (for example TL-retrofit tube, operating at elevated temperature, lifetime
of at least 50.000 hours). The use of yellow organic phosphors derived from perylene,
such as F170 (2-(2,6-diisopropylphenyl)-1,3-dioxo-2,3-dihydro-1H-benzo[5,10]anthra[2,1,9-def]isoquinoline-8-carbonitrile;
CAS Registry no. 936212-95-2 and 676363-16-9) or F83 (diisobutyl 4-cyano-10-isocyanoperylene-3,9-dicarboxylate
mixture with diisobutyl 4-cyano-9-isocyanoperylene-3,10-dicarboxylate ;
CAS Registry no. 100443-95-6), and of Solvent Yellow 98 (2-octadecyl-1H-thioxantheno[2,1,9-def]isoquinoline-1,3(2H)-dione;
CAS Registry no. 12671-74-8) or Disperse Yellow (7-(diethylamino)-3-(6-methylbenzo[d]oxazol-2-yl)-2H-chromen-2-one
;
CAS Registry no. 34564-13-1), results in low lifetimes. These yellow phosphors degrade too fast for use in lighting
applications.
[0011] Hence, it is an aspect of the invention to provide an alternative lighting device,
and especially an alternative light converter, which preferably further at least partly
obviate one or more of above-described drawbacks. It is further an aspect of the invention
to provide an alternative organic luminescent material, especially emitting in the
green and/or yellow, especially for combination with a blue light source, such as
a blue LED, which preferably further at least partly obviates one or more of above-described
drawbacks.
[0012] Here we propose organic phosphors with a similar structure to Solvent Yellow 98 but
with the sulfur atom replaced by oxygen, so called benzoxanthene derivatives. The
specific systems proposed exhibit much longer lifetimes under the irradiation conditions
than known similar prior art systems. Preferentially, the yellow and/or green (and
red) emitting phosphors are in the remote phosphor configuration which may lead to
a total increase in the system efficacy. This configuration is most suitable in low
power low operating temperature applications such as TLED (tube LED configuration,
e.g. LEDs implement in a T8 tube (known in the art of fluorescent lighting)).
[0013] Hence, in a first aspect, the invention provides a lighting device comprising (a)
a light source configured to generate light source light, (b) a light converter configured
to convert at least part of the light source light into visible converter light, wherein
the light converter comprises a matrix containing an organic luminescent material
as defined by formula (I) (wherein the organic luminescent material is especially
configured to provide green and/or yellow light), and (c) optionally a further luminescent
material (especially configured to provide at least red light), with the organic luminescent
material according to formula (I):

with G
1 as defined above, in which A, B, C, J, Q are independently selected from hydrogen,
halogen, R
1, OR
2, NHR
7, and NR
2R
7, wherein R
1 is independently selected from C
2-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl; and wherein R
2 and R
7 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl; and in which G
2-G
9 are independently selected from hydrogen, halogen, R
3, OR
3, NHR
3, and NR
4R
3, wherein R
3 and R
4 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl, as further defined in the accompanying claims.
[0014] In a further aspect, the invention also provides a light converter
per se. Hence, in a further aspect the invention also provides a light converter comprising
a matrix containing an organic luminescent material as defined by formula I (see above),
with G
1 as defined above, in which A, B, C, J, Q are independently selected from hydrogen,
halogen, R
1, OR
2, NHR
7, and NR
2R
7, wherein R
1 is independently selected from C
2-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl; wherein R
2 and R
7 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl; in which G
2-G
9 are independently selected from hydrogen, halogen, R
3, OR
3, NHR
3, and NR
4R
3, wherein R
3 and R
4 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl, as further defined in the accompanying claims. As will be elucidated below,
such matrix may also comprise one or more further luminescent materials, like quantum
dot based materials and/or nitride based materials, and/or other organic luminescent
materials, etc., that may especially luminesce in the red.
[0015] In yet a further aspect, the invention also provides such organic luminescent material
per se. Hence, in a further aspect, the invention also provides an organic luminescent material
as defined by formula I (see above), with G
1 as defined above, in which A, B, C, J, Q are independently selected from hydrogen,
halogen, R
1, OR
2, NHR
7, and NR
2R
7, wherein R
1 is independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl; and wherein R
2 and R
7 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl; in which G
2-G
9 are independently selected from hydrogen, halogen, R
3, OR
3, NHR
3, and NR
4R
3, wherein R
3 and R
4 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl; and wherein in a specific embodiment optionally (i) one or both of G
3 and G
4 are independently selected from R
3 and OR
3, wherein R
3=Y, with D, E, I, L and M independently being selected from hydrogen, halogen, R
5, OR
5, NHR
5, and NR
6R
5, wherein R
5 and R
6 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl, and wherein optionally (ii) G
8 does not include an amine group as further defined in the accompanying claims. Hence,
in embodiments, which may relate to one or more of the lighting device, the light
converter and the organic luminescent material per se, one or more of G
2-G
9 are independently selected from R
3, OR
3, NHR
3, and NR
4R
3, wherein R
3=Y, with D, E, I, L and M independently being selected from hydrogen, halogen, R
5, OR
5, NHR
5, and NR
6R
5, wherein R
5 and R
6 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl.
[0016] It appears that such lighting device, light converter and/or organic luminescent
material, as defined above, and as further elucidated below, may be applied efficiently
and with a good life time under (blue) irradiation. Relative to prior art systems,
a 10-100 fold increase in life time was observed.
[0017] Herein, the term "C
1-C
18alkyl" may relate to a branched C
1-C
18alkyl or an unbranched C
1-C
18alkyl. The term "C
1-C
18alkyl" may relate to an unsubstituted C
1-C
18alkyl or substituted C
1-C
18alky (i.e. C
1-C
18alkyl with one or more substituents). The term "C
1-C
18alkyl" may relate to a linear C
1-C
18alkyl or non-linear C
1-C
18alkyl (which may be substituted or unsubstituted). The term "non-linear" herein may
refer to cyclic, like C
1-C
18 cyclo alkyl.
[0018] Herein, the term "C
2-C
18alkyl" may relate to a branched C
2-C
18alkyl or an unbranched C
2-C
18alkyl. The term "C
2-C
18alkyl" may relate to an unsubstituted C
2-C
18alkyl or substituted C
2-C
18alky (i.e. C
2-C
18alkyl with one or more substituents). The term "C
2-C
18alkyl" may relate to a linear C
2-C
18alkyl or non-linear C
2-C
18alkyl (which may be substituted or unsubstituted). The term "non-linear" herein may
refer to cyclic, like C
2-C
18 cyclo alkyl.
[0019] By way of example, the term "C
1-C
18alkyl" may relate in an embodiment to a linear heptyl group, but may in another embodiment
relate to a methyl substitute cyclo hexane group, with one or more fluor substituents.
C
1-C
18alkyl especially relates to C
1-C
16 alkyl, like C
1-C
8 alkyl, such as C
1-C
4 alkyl.
[0020] Examples of alkyl groups are especially methyl, ethyl, n-propyl, isopropyl, n-butyl,
isobutyl, sec-butyl, tert-butyl, n-pentyl, neo-pentyl, n-hexyl, n-heptyl, n-octyl,
n-nonyl, n-decyl, n-undecyl, n-dodecyl, etc. Examples of cyclo alkyl groups are e.g.
cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc.
[0021] Optionally, the carbon chains of the C
1-C
18alkyl and/or C
2-C
18alkyl may be interrupted by one or more groups which are independently selected from
-O- and -S-. Hence, in an embodiment the term C
1-C
18 alkyl may also relate to an ether or in a variant a polyether. Therefore, in a specific
embodiment C
1-C
18alkyl may also refer to C
1-C
18alkyl comprising one or more ether groups, such as C
nH
2n+1O
m, with n being an integer from 1 to 18, such as 1-16, and with 0≤m≤n/2.
[0022] As for instance A, B, C, J, Q may independently relate to OR
1, G
2-G
9 may independently relate to OR
3, and D, E, I, L and M may independently relate to OR
5, C
1-18alkyl may thus be part of an alkoxy group. For instance, "A" (in G
1) may be methoxy, etc.
[0023] Substituents that may be applied may be selected from fluorine, chlorine, hydroxyl,
cyano, acyl, COOH, carboxylate, alkylcarbonyloxy, carbamoyl, alkylaminocarbonyl, (dialkylamino)carbonyl,
SO
3H, sulfonate, sulfoamino, sulfamide, sulfamoyl, and amidino. In general, the substituents
will be limited to 1-6 substituents, like 1-4 substituents. In a specific embodiment,
the C
1-C
18alkyl is substituted with one or more fluorine atoms. For instance, in an embodiment
C
1-C
18alkyl especially relates to C
nH
2n+1-mF
m with n being an integer from 1 to 18, such as 1-16, and with 0≤m≤2n+1. Hence, the
term "alkyl" and similar terms, may also relate to a substituted alkyl, such as an
alkyl that is fluorinated with one or more fluor substituents.
[0024] Herein, the term "C
6-C
24aryl" may refer to a mono cyclic aromatic aryl group or to a polycyclic aromatic aryl
group. The term "C
6-C
24aryl" may relate to an unsubstituted C
6-C
24aryl or to a substituted C
6-C
24aryl (i.e. C
6-C
24aryl with one or more substituents). C
6-C
24aryl especially relates to C
6-C
16 aryl, like C
6-C
10 aryl. The C
6-C
24aryl may in addition to at least one aryl group, also comprise one or more non-conjugated
cyclic groups.
[0025] Examples of aryl groups are phenyl, naphthyl, indenyl, fluorenyl, anthracenyl, phenanthrenyl,
naphthacenyl, etc. In case the C
6-C
24 aryl comprises one or more aromatic groups and one or more alkyl groups, like methyl
phenyl (C
7), or ethyl phenyl (C
8), the alkyl groups may especially be linear alkyl groups. Also these alkyl groups
may independently comprise one or more substituents. Further, also these alkyl groups
may be interrupted by one or more groups which are independently selected from -O-
and -S-. Hence, in an embodiment such alkyl group may also relate to an ether or in
a variant a polyether.
[0026] Substituents that may be applied may be selected from fluorine, chlorine, hydroxyl,
cyano, acyl, COOH, carboxylate, alkylcarbonyloxy, carbamoyl, alkylaminocarbonyl, (dialkylamino)carbonyl,
SO
3H, sulfonate, sulfoamino, sulfamide, sulfamoyl, and amidino. In general, the substituents
will be limited to 1-6 substituents, like 1-4 substituents. In a specific embodiment,
the C
6-C
24aryl is substituted with one or more fluorine atoms.
[0027] Herein, the term "C
6-C
24heteroaryl" may refer to heteroaromatic, mono- or polycyclic groups. The term "C
6-C
24heteroaryl" may relate to an unsubstituted C
6-C
24heteroaryl or to a substituted C
6-C
24heteroaryl (i.e. C
6-C
24heteroaryl with one or more substituents). C
6-C
24 heteroaryl especially relates to C
6-C
16 heteroaryl, like C
6-C
10 heteroaryl The C
6-C
24heteroary may in addition to at least one heteroaryl group, also comprise one or more
non-conjugated cyclic groups.
[0028] Examples of C
6-C
24heteroyaryls are e.g. 2,5-indenylene, 2,6-indenylene, pyrazinylene, pyridinylene,
pyrimidinylene, 2,4-thiophenylene, 2,5-thiophenylene, 1,3,4-thiadiazol-2,5-ylene,
1,3-thiazol-2,4-ylene, 1,3-thiazol-2,5-ylene, 1,3-oxazol-2,4-ylene, 1,3-oxazol-2,5-ylene,
1,3,4-oxadiazol-2,5-ylene, etc. In case the C
6-C
24heteroyaryl comprises one or more hetero aromatic groups and one or more alkyl groups,
the alkyl groups may especially be linear alkyl groups. Also these aklyl groups may
independently comprise one or more substituents. Further, also these alkyl groups
may be interrupted by one or more groups which are independently selected from -O-
and -S-. Hence, in an embodiment such alkyl group may also relate to an ether or in
a variant a polyether.
[0029] Substituents that may be applied may be selected from fluorine, chlorine, hydroxyl,
cyano, acyl, COOH, carboxylate, alkylcarbonyloxy, carbamoyl, alkylaminocarbonyl, (dialkylamino)carbonyl,
SO
3H, sulfonate, sulfoamino, sulfamide, sulfamoyl, and amidino. In general, the substituents
will be limited to 1-6 substituents, like 1-4 substituents. In a specific embodiment,
the C
6-C
24heteroaryl is substituted with one or more fluorine atoms.
[0030] In an embodiment, wherein one or more of R
1, R
2, R
3, R
4, R
5, R
6, R
7 are available, one or more of these are independently selected from the group consisting
of (i) C
nH
2n+1O
m, with n being an integer from 1 to 18 and with 0≤m≤n/2, (ii) C
nH
2n+1-mF
m with n being an integer from 1 to 18 and with 0≤m≤2n+1, (iii) C
6-C
24aryl comprising one or more ether groups, (iv) C
6-C
24aryl comprising one or more fluor substituents, (v) C
6-C
24heteroaryl comprising one or more ether groups, and (vi) C
6-C
24heteroaryl comprising one or more fluor substituents.
[0031] Halogens herein are especially fluorine, chlorine, even more especially fluorine.
Especially, when one or more halogens are present, the one or more halogens comprise
(only) fluorine.
[0032] The phrase "independently selected from" may indicate that any of the indicated species
may be chosen, independent of the other choices. For instance, in theory G
2 might be hydrogen, G
3 fluorine, G
4 C
1-C
18alkyl, G
5 OR
3 with R
3 being C
1-C
18alkyl, G
6 NR
4R
3, with R
3 being C
1-C
18alkyl and with R
4 being C
6-C
24aryl, G
7 C
6-C
24heteroaryl, G
8 and G
9 halogen substituted C
1-C
18alkyl. In general however, at least four of G
2-G
9 are hydrogen, and at least two, especially at least three of A,B,C,J,Q are hydrogen.
Further, when R
3=Y, especially at least two, more especially at least three of D,E,I,L,M are hydrogen.
[0033] In an embodiment, G
8 does not include an amine group. The absence of such amine group may be beneficial
for stability. Especially, a covalent bond between the phenyl C directly to a primary,
secondary or tertiary amine may be avoided. Optionally, the G
8 group or radical may also not comprise an amide group. In a specific embodiment,
G
8 is selected from hydrogen, halogen, R
3, and OR
3, wherein R
3 and R
4 are independently selected from C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl, wherein R
3 and R
4 especially do not comprise an amine group. Especially, G
8 comprises hydrogen or halogen.
[0034] Good optical results in terms of stability and/or efficiency and/or spectral distribution
of the emission can be obtained with one or more of isopropyl and tertbutyl groups
associated to G
1. Hence, in a specific embodiment one, or especially two of A, B, and C are independently
selected from the group consisting of isopropyl and tertbutyl. In a specific embodiment,
A and C are isopropyl, and G
2, G
5, G
7-G
9, B, J and Q are hydrogen. Yet in another embodiment, B and C are tertbutyl, and G
2, G
5, G
7-G
9, A, J and Q are hydrogen.
[0035] Further, alternatively or additionally substitution of G
3 and/or G
4 with an aryl or aryloxy (i.e. -O-aryl, such as OR
3, wherein R
3=Y) group provides good organic luminescent materials. Hence, in an embodiment one
or both of G
3 and G
4 are independently selected from R
3 and OR
3, wherein R
3=Y (see chemical formulas above), with D, E, I, L and M independently being selected
from hydrogen, halogen, C
1-C
18alkyl, C
6-C
24aryl, and C
6-C
24heteroaryl. Especially, D, E, I, L and M are independently being selected from hydrogen
and halogen, especially hydrogen and fluorine, even more especially hydrogen. Hence,
in a specific embodiment, one or both of G
3 and G
4 are independently selected from R
3 and OR
3, wherein R
3=Y, with D, E, I, L and M being hydrogen.
[0036] In a specific embodiment, one or both of G
3 and G
4 are independently selected from R
3 and OR
3, wherein R
3=Y, with D, E, I, L and M being hydrogen, and wherein G
2, G
5, G
7-G
9, J and Q are hydrogen. Especially R
3=Y, with D, E, I, L and M being hydrogen.
[0037] In an embodiment, one or more of G
2-G
9 may independently also comprise an oxygen-containing alkyl group C
nH2
n+1O
m, n being an integer from 1 to 16 and 0≤m≤n/2, such as an ether or alcohol, especially
an ether. Alternatively or additionally, one or more of D, E, I, L and M may independently
also comprise an oxygen-containing alkyl group C
nH2
n+1O
m, n being an integer from 1 to 16 and 0≤m≤n/2. Especially, minimally two of D, E,
I, L and M groups are hydrogen atoms. Further, in a specific embodiment G
3 is a C
6H
5O-group and G
2, G
4-G
9 is hydrogen. In yet another embodiment, G
2-G
9 is hydrogen.
[0038] In a specific embodiment, each of A, B, C, J and Q independently comprise a group
selected from hydrogen, fluorine, chlorine, isopropyl, t-butyl, methoxy, an alkyl
with up to 16 carbon atoms, and an oxygen containing alkyl with up to 16 carbon atoms.
[0039] Further, as will be elucidated below the matrix may especially comprise an aromatic
polyester, or a copolymer thereof such as e.g. polyglycolide or polyglycolic acid
(PGA), polylactic acid (PLA), polycaprolactone (PCL), polyethylene adipate (PEA),
polyhydroxy alkanoate (PHA), polyhydroxy butyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
(PHBV), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene
terephthalate (PTT), polyethylene naphthalate (PEN); especially, the matrix may comprise
polyethylene terephthalate (PET). Further, as will also be elucidated below the matrix
may comprise a further luminescent material embedded in the matrix.
[0040] As indicated above, organic phosphors (organic luminescent materials) may suffer
from a relatively low photo-chemical stability. Their stability may strongly depend
on the temperature of the material and on the amount of light that it converts. For
this reason, organic phosphors may be suitable candidates when used in the remote
configuration (see below). A lighting assembly using organic remote phosphor is relatively
cheap because of the use of relatively cheap organic luminescent material. Furthermore,
organic luminescent materials allow an easy design of a specific organic luminescent
material which has a light emission spectrum anywhere in visible spectrum. Such molecules
can be synthesized and depending on the molecular structure it emits a specific light.
[0041] The above described organic luminescent material is of the benzoxanthene derivative
type. Benzoxanthene derivative are known in the art and are for instance described
in
US3748330.
[0042] The above described organic luminescent material may be well excitable in the blue
and/or UV.
[0043] The term "organic luminescent material" may especially refer to an organic material
that has luminescent properties (i.e. can emit light upon excitation (by one or more
of UV and blue light)). As the organic luminescent material of formula I emits especially
at least in the green and/or yellow, the organic luminescent material is herein also
indicated as green and/or yellow emitter or green and/or yellow emitting luminescent
material or green and/or yellow luminescent material. However, the organic luminescent
material of formula I may also remit in e.g. the red.
[0044] The organic luminescent material may be applied in the lighting device as defined
herein. Such lighting device may for instance comprise a TLED (tube with LED(s) within
the tube, such as a T8 tube), which is a kind of retrofit lamp. The organic luminescent
material may also be applied in a light bulb with LED(s) within the bulb, which is
a kind of retrofit incandescent lamp. In both cases, the organic luminescent material
may be applied remote, such as on the upstream face of the transmissive envelope (i.e.
the inner face of the transmissive envelope.
[0045] Optionally, the matrix may be used as transmissive envelope of a lighting device;
in other words: the transmissive envelope substantially consists of the matrix.
[0046] The term light converter may refer to a system that is configured to convert light
from a first wavelength into light of a second wavelength. Especially, UV and/or blue
light (excitation wavelength) may be (at least partially) converted into visible light
(of higher wavelength than the excitation wavelength). Another term for "light converter"
is "wavelength converter".
[0047] The light converter may be in the form of for instance particles, flakes, a film,
a plate, etc. In a specific embodiment, the term light converter may include a self-supporting
layer.
[0048] Hence, in an embodiment, the light converter is selected from the group consisting
of a coating, a self-supporting layer, and a plate; which light converter is thus
especially solid at room temperature, especially even up to 100 °C, especially even
up to 150 °C, more especially even up to 200 °C. The light converter may be flexible
or may be rigid. Further, the light converter may be flat or curved (in one or two
dimensions). Further, optionally the light converter may comprise outcoupling structures
at at least part of the external surface of the light converter.
[0049] The light converter may comprise one or more parts, like layers on top of each other.
Such parts may comprise different luminescent materials or luminescent materials in
different concentration. However, at least part of the light converter comprises the
(red) organic luminescent material.
[0050] The matrix may especially comprise a matrix material and the above indicated materials
such as the organic luminescent material, and optionally further luminescent material,
etc. The organic luminescent material(s) and optionally other luminescent materials
may in an embodiment especially be evenly distributed throughout the matrix. However,
the light converter may also comprise two or more segments, wherein two or more segments
have different compositions at least with respect to the luminescent material(s),
e.g. with respect to type and/or concentration of the luminescent material(s).
[0051] The luminescent material(s) (i.e. at least the organic luminescent material according
to formula I, but optionally also including one or more further luminescent materials),
may in an embodiment molecularly be distributed through the matrix. Alternatively
or additionally, the luminescent material(s) are available as particles, optionally
having a coating. In the latter embodiment, coated particles may be embedded in the
matrix. The coating may especially be applied to seal such particle from H
2O and/or O
2.
[0052] Especially, the matrix material is transmissive for light having a wavelength selected
from the range of 380-750 nm. For instance, the matrix material may be transmissive
for blue, and/or green, and/or red light. Especially, the matrix material is transmissive
for at least the entire range of 420-680 nm. Especially, the matrix material may have
a light transmission in the range of 50-100 %, especially in the range of 70-100%,
for light generated by the light source of the lighting unit (see also below) and
having a wavelength selected from the visible wavelength range. In this way, the matrix
material is transmissive for visible light from the lighting unit. The transmission
or light permeability can be determined by providing light at a specific wavelength
with a first intensity to the material and relating the intensity of the light at
that wavelength measured after transmission through the material, to the first intensity
of the light provided at that specific wavelength to the material (see also E-208
and E-406 of the
CRC Handbook of Chemistry and Physics, 69th edition, 1088-1989). The light converter may be transparent or translucent, but may especially be transparent.
Especially, the light converter is substantially transparent and/or does not substantially
scatter light. When the light converter is transparent, light of the light source
may not entirely be absorbed by the light converter. Especially when using blue light,
this may be of interest, as the blue light may be used to excite the light luminescent
materials and may be used to provide a blue component (in white light).
[0053] The matrix (material) may comprises one or more materials selected from the group
consisting of a transmissive organic material support, such as selected from the group
consisting of PE (polyethylene), PP (polypropylene), PEN (polyethylene napthalate),
PC (polycarbonate), polymethylacrylate (PMA), polymethylmethacrylate (PMMA) (Plexiglas
or Perspex), cellulose acetate butyrate (CAB), silicone, polyvinylchloride (PVC),
polyethylene terephthalate (PET), (PETG) (glycol modified polyethylene terephthalate),
PDMS (polydimethylsiloxane), and COC (cyclo olefin copolymer). However, in another
embodiment the matrix (material) may comprise an inorganic material. Preferred inorganic
materials are selected from the group consisting of glasses, (fused) quartz, transmissive
ceramic materials, and silicones. Also hybrid materials, comprising both inorganic
and organic parts may be applied. Especially preferred are PMMA, PET, transparent
PC, or glass as material for the matrix (material). Even more especially, the matrix
comprises polyethylene terephthalate (PET) as this matrix seems to give the best optical
properties compared to other matrices with the same luminescent materials(s). The
organic luminescent material degrades (under influence of light source irradiation)
slowest in PET. Herein, the term "PET" may also refer to PET-G (Polyethylene Terephtalate
Glycol-modified or optional other modifications. Hence, the matrix especially comprises
a polymeric material, that is especially transmissive for at least part of light generated
by the organic luminescent material.
[0054] The light converter may especially be made by combining the luminescent material(s)
and optionally other ingredients and one or more precursors of the matrix, followed
by a synthesis of the matrix. For instance, in case of polymeric matrix materials
this may be done by using monomeric precursors of the polymer and polymerizing the
monomeric precursors, like by step-growth polymerization, or by radical chain polymerization,
etc., in the presence of the luminescent material(s) and optionally other ingredients,
to provide the polymeric matrix. Another option may be using as starting material(s)
molecules, especially polymers, that are curable, and curing these molecules, especially
polymers, in the presence of the luminescent material(s) and optionally other ingredients,
to provide the matrix. Hence, especially the matrix is a polymeric matrix.
[0055] In a specific embodiment, one or more of G
1, G
2, G
3, G
4, G
5, G
6, G
7, G
8 and G
9, comprise a covalent link with the matrix (material), especially one or more of G
1 and G
8, comprise a covalent link with the matrix (thus especially a polymeric matrix). This
may for instance be obtained by providing one or more of these groups, such as one
or more of G
1 and G
6, with a curable group or a polymerizable group. This may further facilitate embedding
the organic luminescent material in the matrix. Hence, in an embodiment, one or more
of G
1, G
2, G
3, G
4, G
5, G
6, G
7, G
8 and G
9 may comprise a curable or cross-linkable group.
[0056] The matrix may be coated or enclosed by a seal or coating. The coating or seal may
especially be applied to seal such matrix from H
2O and/or O
2.
[0057] As indicated above, the light converter may especially comprise a green and/or yellow
luminescent material and optionally also a red luminescent material. The light converter
may comprise a plurality of luminescent materials, of which at least one comprises
an organic luminescent material according to formula I.
[0058] The term "formula (I)" may also be indicated as "chemical formula (I)". However,
the light converter may also comprise a plurality of organic luminescent materials
according to formula I. Hence, in an embodiment, the term "organic luminescent material"
may relate to a combination of different organic luminescent material all complying
with formula (I).
[0059] Further, the light converter especially comprises an further luminescent material
(see further below). However, the light converter may also comprise a plurality of
further luminescent materials. Hence, in an embodiment the light converter may comprise
one or more organic luminescent materials according to formula I, and optionally one
or more other organic luminescent materials, and optionally one or more inorganic
luminescent materials. The light converter may further comprise one or more scattering
materials, and optionally other materials.
[0060] Hence, one or more further luminescent materials may be applied. The one or more
further luminescent materials may also be embedded in the light converter. Alternatively
or additionally, the one or more further luminescent materials may be available in
a coating on the luminescent light converter. Alternatively or additionally, the one
or more further luminescent materials may be arranged within the lighting device separate
from the light converter. Especially, the one or more further luminescent materials
comprise a red emitting phosphor. The term "further luminescent material" especially
refers to an inorganic material that has luminescent properties (i.e. can emit light
upon excitation (by one or more of UV and blue light)). The further luminescent material
may especially be configured to emit at least in the red, though other wavelengths
are not excluded, like (also) in the yellow, green, etc. The term "further luminescent
material" especially refers to an inorganic material that has luminescent properties
(i.e. can emit light upon excitation (by one or more of UV and blue light)). However,
the further luminescent material may in other embodiments comprise an organic luminescent
material (different from the organic luminescent material(s) according to formula
I).
[0061] Hence, the further luminescent material as indicated above may especially be configured
to provide red light (and optionally other light). Hence, the further luminescent
material may especially be configured to convert at least part of the light of the
light source into at least red light. The further luminescent material, and especially
an further luminescent material (configured to provide red light), may be comprised
by the light converter, especially the matrix, but may also be outside the light converter,
such as a coating on the light converter.
[0062] The further luminescent material may comprise quantum dots (QDs). Amongst other narrow
band emitters quantum dots are highly suitable for this purpose. Quantum dots are
small crystals of semiconducting material generally having a width or diameter of
only a few nanometers. When excited by incident light, a quantum dot emits light of
a color determined by the size and material of the crystal. Light of a particular
color can therefore be produced by adapting the size of the dots. This means that
by using quantum dots any spectrum can be obtained as they are narrow band emitters.
[0063] Most known quantum dots with emission in the visible range are based on cadmium selenide
(CdSe) with shell such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium free
quantum dots such as indium phosphide (InP), and copper indium sulfide (CuInS
2) and/or silver indium sulfide (AgInS
2) can also be used. Quantum dots show very narrow emission band and thus they show
saturated colors. Furthermore, the emission color can easily be tuned by adapting
the size of the quantum dots.
[0064] The quantum dots or luminescent nanoparticles, which are herein indicated as light
converter nanoparticles, may for instance comprise group II-VI compound semiconductor
quantum dots selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe,
HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe,
CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe,
CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe. In another embodiment,
the luminescent nanoparticles may for instance be group III-V compound semiconductor
quantum dots selected from the group consisting of GaN, GaP, GaAs, AlN, AlP, AlAs,
InN, InP, InAs, GaNP, GaNAs, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlNP,
GaAlNAs, GaAlPAs, GaInNP, GaInNAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs. In yet a
further embodiment, the luminescent nanoparticles may for instance be I-III-VI2 chalcopyrite-type
semiconductor quantum dots selected from the group consisting of CuInS
2, CuInSe
2, CuGaS
2, CuGaSe
2, AgInS
2, AgInSe
2, AgGaS
2, and AgGaSe
2. In yet a further embodiment, the luminescent nanoparticles may for instance be I-V-VI2
semiconductor quantum dots, such as selected from the group consisting of LiAsSe
2, NaAsSe
2 and KAsSe
2. In yet a further embodiment, the luminescent nanoparticles may for instance be a
group IV-VI compound semiconductor nano crystals such as SbTe. In a specific embodiment,
the luminescent nanoparticles are selected from the group consisting of InP, CuInS
2, CuInSe
2, CdTe, CdSe, CdSeTe, AgInS
2 and AgInSe
2. In yet a further embodiment, the luminescent nanoparticles may for instance be one
of the group II-VI, III-V, I-III-V and IV-VI compound semiconductor nano crystals
selected from the materials described above with inside dopants such as ZnSe:Mn, ZnS:Mn.
The dopant elements could be selected from Mn, Ag, Zn, Eu, S, P, Cu, Ce, Tb, Au, Pb,
Tb, Sb, Sn and Tl. Herein, the luminescent nanoparticles based luminescent material
may also comprise different types of QDs, such as CdSe and ZnSe:Mn.
[0065] It appears to be especially advantageous to use II-VI quantum dots. Hence, in an
embodiment the semiconductor based luminescent quantum dots comprise II-VI quantum
dots, especially selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe,
ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe,
HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS,
CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, even
more especially selected from the group consisting of CdS, CdSe, CdSe/CdS and CdSe/CdS/ZnS.
[0066] In an embodiment, Cd-free QDs are applied. In a specific embodiment, the light converter
nano-particles comprise III-V QDs, more specifically an InP based quantum dots, such
as a core-shell InP-ZnS QDs. Note that the terms "InP quantum dot" or "InP based quantum
dot" and similar terms may relate to "bare" InP QDs, but also to core-shell InP QDs,
with a shell on the InP core, such as a core-shell InP-ZnS QDs, like a InP-ZnS QDs
dot-in-rod.
[0067] Typical dots are made of binary alloys such as cadmium selenide, cadmium sulfide,
indium arsenide, and indium phosphide. However, dots may also be made from ternary
alloys such as cadmium selenide sulfide. These quantum dots can contain as few as
100 to 100,000 atoms within the quantum dot volume, with a diameter of 10 to 50 atoms.
This corresponds to about 2 to 10 nanometers. For instance, spherical particles such
as CdSe, InP, or CuInSe
2, with a diameter of about 3 nm may be provided. The luminescent nanoparticles (without
coating) may have the shape of spherical, cube, rods, wires, disk, multi-pods, etc.,
with the size in one dimension of less than 10 nm. For instance, nanorods of CdSe
with the length of 20 nm and a diameter of 4 nm may be provided. Hence, in an embodiment
the semiconductor based luminescent quantum dots comprise core-shell quantum dots.
In yet another embodiment, the semiconductor based luminescent quantum dots comprise
dots-in-rods nanoparticles. A combination of different types of particles may also
be applied. For instance, core-shell particles and dots-in-rods may be applied and/or
combinations of two or more of the afore-mentioned nano particles may be applied,
such as CdS and CdSe. Here, the term "different types" may relate to different geometries
as well as to different types of semiconductor luminescent material. Hence, a combination
of two or more of (the above indicated) quantum dots or luminescent nano-particles
may also be applied.
[0068] One example, such as derived from
WO 2011/031871, of a method of manufacturing a semiconductor nanocrystal is a colloidal growth process.
[0069] In an embodiment, nanoparticles can comprise semiconductor nanocrystals including
a core comprising a first semiconductor material and a shell comprising a second semiconductor
material, wherein the shell is disposed over at least a portion of a surface of the
core. A semiconductor nanocrystal including a core and shell is also referred to as
a "core/shell" semiconductor nanocrystal.
[0070] For example, the semiconductor nanocrystal can include a core having the formula
MX, where M can be cadmium, zinc, magnesium, mercury, aluminum, gallium, indium, thallium,
or mixtures thereof, and X can be oxygen, sulfur, selenium, tellurium, nitrogen, phosphorus,
arsenic, antimony, or mixtures thereof. Examples of materials suitable for use as
semiconductor nanocrystal cores include, but are not limited to, ZnO, ZnS, ZnSe, ZnTe,
CdO, CdS, CdSe, CdTe, MgS, MgSe, GaAs, GaN, GaP, GaSe, GaSb, HgO, HgS, HgSe, HgTe,
InAs, InN, InP, InSb, AlAs, AIN, AlP, AlSb, TIN, TIP, TIAs, TISb, PbO, PbS, PbSe,
PbTe, Ge, Si, an alloy including any of the foregoing, and/or a mixture including
any of the foregoing, including ternary and quaternary mixtures or alloys.
[0071] The shell can be a semiconductor material having a composition that is the same as
or different from the composition of the core. The shell comprises an overcoat of
a semiconductor material on a surface of the core semiconductor nanocrystal can include
a Group IV element, a Group II-VI compound, a Group II-V compound, a Group III- VI
compound, a Group III-V compound, a Group IV-VI compound, a Group I-III-VI compound,
a Group II-IV-VI compound, a Group II-IV-V compound, alloys including any of the foregoing,
and/or mixtures including any of the foregoing, including ternary and quaternary mixtures
or alloys. Examples include, but are not limited to, ZnO, ZnS, ZnSe, ZnTe, CdO, CdS,
CdSe, CdTe, MgS, MgSe, GaAs, GaN, GaP, GaSe, GaSb, HgO, HgS, HgSe, HgTe, InAs, InN,
InP, InSb, AlAs, AIN, AlP, AlSb, TIN, TIP, TIAs, TISb, PbO, PbS, PbSe, PbTe, Ge, Si,
an alloy including any of the foregoing, and/or a mixture including any of the foregoing.
For example, ZnS, ZnSe or CdS overcoatings can be grown on CdSe or CdTe semiconductor
nanocrystals.
[0072] Examples of semiconductor nanocrystal (core)shell materials include, without limitation:
red (e.g., (CdSe)ZnS (core)shell), green (e.g., (CdZnSe)CdZnS (core)shell, etc.),
and blue (e.g., (CdS)CdZnS (core)shell (see further also above for examples of specific
light converter nanoparticles, based on semiconductors.
[0073] Therefore, in a specific embodiment, the light converter nanoparticles are selected
from the group consisting of core-shell nano particles, with the cores and shells
comprising one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS,
CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe,
CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS,
CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, GaN, GaP, GaAs, AlN, AlP, AlAs, InN,
InP, InAs, GaNP, GaNAs, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlNP, GaAlNAs,
GaAlPAs, GaInNP, GaInNAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs.
[0074] In general, the cores and shells comprise the same class of material, but essentially
consist of different materials, like a ZnS shell surrounding a CdSe core, etc.
[0075] Additionally or alternatively, the further luminescent material may also comprise
other luminescent materials, such as one or more of selected from the group consisting
of divalent europium containing nitride luminescent material or a divalent europium
containing oxonitride luminescent material, such as one or more materials selected
from the group consisting of (Ba,Sr,Ca)S:Eu, (Mg,Sr,Ca)AlSiN
3:Eu and (Ba,Sr,Ca)
2Si
5N
8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces
one or more of the indicated divalent cations. In general, Eu will not be present
in amounts larger than 10% of the cation, especially in the range of about 0.5-10%,
more especially in the range of about 0.5-5% relative to the cation(s) it replaces.
The term ":Eu" or ":Eu
2+", indicates that part of the metal ions is replaced by Eu (in these examples by Eu
2+). For instance, assuming 2% Eu in CaAlSiN
3 :Eu, the correct formula could be (Ca
0.98Eu
0.02)AlSiN
3. Divalent europium will in general replace divalent cations, such as the above divalent
alkaline earth cations, especially Ca, Sr or Ba. The material (Ba,Sr,Ca)S:Eu can also
be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting
of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound
calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu
is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca).
Further, the material (Ba,Sr,Ca)
2Si
5N
8:Eu can also be indicated as M
2Si
5N
8:Eu, wherein M is one or more elements selected from the group consisting of barium
(Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound Sr
and/or Ba. In a further specific embodiment, M consists of Sr and/or Ba (not taking
into account the presence of Eu), especially 50-100%, especially 50-90% Ba and 50-0%,
especially 50-10% Sr, such as Ba
1.5Sr
0.5Si
5N
8:Eu, (i.e. 75 % Ba; 25% Sr). Here, Eu is introduced and replaces at least part of
M i.e. one or more of Ba, Sr, and Ca). Likewise, the material (Ba,Sr,Ca)AlSiN
3:Eu can also be indicated as MAlSiN
3:Eu wherein M is one or more elements selected from the group consisting of barium
(Ba)
5 strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium
or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced
and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca). Preferably,
in an embodiment the further luminescent material comprises (Ca,Sr,Mg)AlSiN
3:Eu, preferably CaAlSiN
3:Eu. Further, in another embodiment, which may be combined with the former, the further
luminescent material comprises (Ca,Sr,Ba)
2Si
5N
8:Eu, preferably (Sr,Ba)
2Si
5N
8 :Eu. The terms "(Ca,Sr,Ba)" indicate that the corresponding cation may be occupied
by calcium, strontium or barium. It also indicates that in such material corresponding
cation sites may be occupied with cations selected from the group consisting of calcium,
strontium and barium. Thus, the material may for instance comprise calcium and strontium,
or only strontium, etc.
[0076] The further luminescent material may also comprise one or more luminescent materials
selected from the group consisting of a trivalent cerium containing garnet (see above)
and a trivalent cerium containing oxonitride. The oxonitride materials are in the
art often also indicated as oxynitride materials.
[0077] Hence, in an embodiment the further luminescent material is configured to provide
at least red light, the organic luminescent material is configured to provide at least
green and/or yellow light, and especially the light source is configured to provide
blue light. As indicated the further luminescent material comprises a quantum dot
based luminescent material.
[0078] Hence, in an embodiment the light source is configured to provide blue light, the
lighting device further comprises a further luminescent material configured to provide
red light, wherein the further luminescent material comprises a luminescent material
selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Mg,Sr,Ca)AlSiN
3:Eu and (Ba,Sr,Ca)
2Si
5N
8:Eu (and optionally a quantum dot based luminescent material (see also above))(and
optionally an organic red luminescent (see also below)). Alternatively or additionally,
the further luminescent material comprises a quantum dot based luminescent material.
The further luminescent material may be embedded in the matrix and/or may be applied
as coating to the matrix. Additionally or alternatively, the further luminescent material
may also be arranged elsewhere in the lighting device, but may still be configured
to convert at least part of the light source light into visible light, that may optionally
complement the light of the organic luminescent material. Hence, in a specific embodiment
the lighting device further comprises a quantum dot based luminescent material embedded
in the matrix.
[0079] In yet another embodiment, the further luminescent material comprises an organic
luminescent materials, especially an organic red luminescent material. In a further
specific embodiment, the further luminescent material comprises an organic luminescent
material as defined by formula (II):

in which:
- G1 and G6 independently comprise a group selected from a linear alkyl, a branched alkyl, an
oxygen-containing alkyl, a cycloalkyl, a naphtyl, and Y;
∘ wherein each of A, B, C, J and Q independently comprise a group selected from hydrogen,
fluorine, chlorine, isopropyl, t-butyl, methoxy, an alkyl with up to 16 carbon atoms,
and an oxygen containing alkyl with up to 16 carbon atoms;
- G2, G3, G4 and G5 independently comprise a group selected from hydrogen, fluorine, chorine, isopropyl,
t-butyl, methoxy, alkyl with up to 16 carbon atoms, and oxygen-containing alkyl with
up to 16 carbon atoms, and X;
∘ wherein each of D, E, I, L and M independently comprise a group selected from hydrogen,
fluorine, chlorine, isopropyl, t-butyl, methoxy, alkyl with up to 16 carbon atoms,
and an oxygen-containing alkyl with up to 16 carbon atoms;
and in which
at least two selected from G
2, G
3, G
4, and G
5 at least comprise X, wherein independently at least one of D, E, I, L and M of at
least two of said at least two selected from G
2, G
3, G
4, and G
5 comprise a group selected from fluorine and chlorine, especially fluorine.
[0081] The term "further luminescent material" may thus also relate to a plurality of different
further luminescent materials. The further luminescent material may be comprised by
the light converter, such as embedded in the matrix, like especially the organic luminescent
material, or may be outside the light converter, such as a layer on the light converter,
or may be elsewhere in the lighting device. Combinations of two or more of such configurations
are also possible. Hence, in an embodiment the further luminescent material, such
as the quantum dot based luminescent material, is embedded in the matrix.
[0082] As indicated above, the lighting device comprises (a) a light source configured to
generate light source light, and (b) a light converter configured to convert at least
part of the light source light into visible converter light.
[0083] The light converter, or especially the luminescent material, is configured to convert
at least part of the light source light. In order words, one may say that the light
source is radiationally coupled to the light converter, especially the luminescent
material. When the light source comprises a substantially UV light emitting light
source, the luminescent material may be configured to convert substantially all light
source light that impinges on the luminescent material. In case the light source is
configure to generate blue light, the luminescent material may partly convert the
light source light. Dependent upon the configuration, a part of the remaining light
source light may be transmitted through a layer comprising the luminescent material.
Here, the term may relate to one or more of the organic luminescent material and the
further luminescent material.
[0084] The term light source may in principle relate to any light source known in the art,
but may especially refers to a LED-based light source, herein further indicated as
LED. The description below will - for the sake of understanding - only addresses LED-based
light sources. The light source is configured to provide UV and/or blue light. In
a preferred embodiment, the light emitting diode is configured to generate LED light
with a blue component. In other words, the light source comprises a blue LED. Hence,
in an embodiment, the light source is configured to generate blue light. Especially,
the LED is a solid state LED.
[0085] In yet another embodiment, the light emitting diode is configured to generate LED
light with a UV component. In other words, the light source comprises a UV LED. When
a UV light source is applied and blue or white light is desired, as blue component,
for instance the well-known materials BaMgAl
10O
17:Eu
2+ and/or (Sr,Ba,Ca)
5(PO
4)
3Cl:Eu
2+ may be applied. However, also other luminescent materials that are able to convert
UV light into blue light may alternatively or additionally be applied. Such blue luminescent
material may be applied as part of the light source, or remote, and may optionally
(also) be comprised by the light converter. All luminescent materials described herein
may be radiationally coupled with the light source, though optionally one or more
luminescent materials are radiationally coupled with one or more other luminescent
materials (i.e. they are configured to receive mission light of those one or more
other luminescent materials, and can get be excited by that emission light).
[0086] Preferably, the light source is a light source that during operation emits at least
light at a wavelength selected from the range of 200-490 nm, especially a light source
that during operation emits at least light at wavelength selected from the range of
400-490 nm, even more especially in the range of 440-490 nm. This light may partially
be used by the luminescent material(s) (see below). In a specific embodiment, the
light source comprises a solid state LED light source (such as a LED or laser diode).
The term "light source" may also relate to a plurality of light sources, such as 2-20
(solid state) LED light sources. Hence, the term LED may also refer to a plurality
of LEDs. Hence, in a specific embodiment, the light source is configured to generate
blue light. In a further embodiment, the lighting device might be applied as back
lighting unit in an LCD application. Hence, the invention provides in a further aspect
a liquid crystal display device comprising a back lighting unit, wherein the back
lighting unit comprises one or more lighting devices as defined herein.
[0087] The term white light herein, is known to the person skilled in the art. It especially
relates to light having a correlated color temperature (CCT) between about 2000 and
20000 K, especially 2700-20000 K, for general lighting especially in the range of
about 2700 K and 6500 K, and for backlighting purposes especially in the range of
about 7000 K and 20000 K, and especially within about 15 SDCM (standard deviation
of color matching) from the BBL (black body locus), especially within about 10 SDCM
from the BBL, even more especially within about 5 SDCM from the BBL.
[0088] In an embodiment, the light source may also provide light source light having a correlated
color temperature (CCT) between about 5000 and 20000 K, e.g. direct phosphor converted
LEDs (blue light emitting diode with thin layer of phosphor for e.g. obtaining of
10000 K). Hence, in a specific embodiment the light source is configured to provide
light source light with a correlated color temperature in the range of 5000-20000
K, even more especially in the range of 6000-20000 K, such as 8000-20000 K. An advantage
of the relative high color temperature may be that there may be a relative high blue
component in the light source light.
[0089] The lighting device comprises at least the light converter comprising the organic
luminescent material according to formula I. Other (further) luminescent materials,
may also be present. The one or more further luminescent materials may each individually
be comprised by the matrix but may also be provides as coating or layer on the matrix,
or may be arranged elsewhere in the lighting device.
[0090] The lighting device may especially be configured to be able to provide white light.
Optionally, the lighting device is configured to provide colored light or is configured
to be able to provide color light and white light, depending upon how the lighting
device is controlled.
[0091] The terms "violet light" or "violet emission" especially relates to light having
a wavelength in the range of about 380-440 nm. The terms "blue light" or "blue emission"
especially relates to light having a wavelength in the range of about 440-490 nm (including
some violet and cyan hues). The terms "green light" or "green emission" especially
relate to light having a wavelength in the range of about 490-560 nm. The terms "yellow
light" or "yellow emission" especially relate to light having a wavelength in the
range of about 540-570 nm. The terms "orange light" or "orange emission" especially
relate to light having a wavelength in the range of about 570-600. The terms "red
light" or "red emission" especially relate to light having a wavelength in the range
of about 600-750 nm. The term "pink light" or "pink emission" refers to light having
a blue and a red component. The terms "visible", "visible light" or "visible emission"
refer to light having a wavelength in the range of about 380-750 nm.
[0092] The light source may be configured in a chamber, with reflective wall(s) (such as
coated with a reflective material like TiO
2), and a light transmissive window. In an embodiment, the window is the light conversion
layer. In yet a further embodiment, the window comprises the light conversion layer.
This layer may be arranged upstream of the window or downstream of the window. In
yet a further embodiment, light conversion layers are applied at both sides of the
window.
[0093] The terms "upstream" and "downstream" relate to an arrangement of items or features
relative to the propagation of the light from a light generating means (here the especially
the first light source), wherein relative to a first position within a beam of light
from the light generating means, a second position in the beam of light closer to
the light generating means is "upstream", and a third position within the beam of
light further away from the light generating means is "downstream".
[0094] It may be advantageous, in view of efficiency and/or stability, to arrange the light
converter (and optionally also other luminescent material(s) not within the light
converter), at a non-zero distance, such as 0.5-50 mm, like 1-50 mm, from the light
source. Hence, in an embodiment, the light converter may be configured at a non-zero
distance of the light source. For instance, the light converter, or especially the
(organic) luminescent material(s), may be applied to or may be comprised by a window
of the lighting unit. Hence, in an embodiment, the light converter is configured at
a non-zero distance from the light source. Note however that the invention is not
limited to applications wherein the distance between the light converter and the light
source is non-zero. The invention, and the herein described specific embodiments,
may be also applied in other embodiments wherein the light source and light converter
are in physical contact. In such instances, the light converter may especially be
configured in physical contact with e.g. a LED die.
[0095] In case the light source is configured to provide blue light, the luminescent material
may be configured to convert only part of the light source light. In an embodiment,
the blue light of the light source and the light of the organic luminescent material
light and the light of the optional further luminescent material, such as a nano particles
based luminescent material, together may in an embodiment provide white light.
[0096] The term "substantially" herein, such as in "substantially all emission" or in "substantially
consists", will be understood by the person skilled in the art. The term "substantially"
may -also include embodiments with "entirely", "completely"; "all", etc. Hence, in
embodiments the adjective substantially may also be removed. Where applicable, the
term "substantially" may also relate to 90% or higher, such as 95% or higher, especially
99% or higher, even more especially 99.5% or higher, including 100%. The term "comprise"
includes also embodiments wherein the term "comprises" means "consists of'. The term
"and/or" especially relates to one or more of the items mentioned before and after
"and/or". For instance, a phrase "item 1 and/or item 2" and similar phrases may relate
to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer
to "consisting of' but may in another embodiment also refer to "containing at least
the defined species and optionally one or more other species".
[0097] Furthermore, the terms first, second, third and the like in the description and in
the claims, are used for distinguishing between similar elements and not necessarily
for describing a sequential or chronological order. It is to be understood that the
terms so used are interchangeable under appropriate circumstances and that the embodiments
of the invention described herein are capable of operation in other sequences than
described or illustrated herein.
[0098] The devices herein are amongst others described during operation. As will be clear
to the person skilled in the art, the invention is not limited to methods of operation
or devices in operation.
[0099] It should be noted that the above-mentioned embodiments illustrate rather than limit
the invention, and that those skilled in the art will be able to design many alternative
embodiments without departing from the scope of the appended claims. In the claims,
any reference signs placed between parentheses shall not be construed as limiting
the claim. Use of the verb "to comprise" and its conjugations does not exclude the
presence of elements or steps other than those stated in a claim. The article "a"
or "an" preceding an element does not exclude the presence of a plurality of such
elements. The mere fact that certain measures are recited in mutually different dependent
claims does not indicate that a combination of these measures cannot be used to advantage.
[0100] The invention further applies to a device comprising one or more of the characterizing
features described in the description and/or shown in the attached drawings. The invention
further pertains to a method or process comprising one or more of the characterizing
features described in the description and/or shown in the attached drawings.
[0101] The various aspects discussed in this patent can be combined in order to provide
additional advantages. Furthermore, some of the features·can form the basis for one
or more divisional applications.
[0102] In yet a further embodiment, the invention provides a lighting device, as described
herein, with the organic luminescent material of formula I, and/or a light converter,
as described herein, with the organic luminescent material of formula I, and/or the
organic luminescent material of formula I, in which A, B, C, J, Q are independently
selected from hydrogen, halogen, R
1, OR
2, NHR
7, and NR
2R
7, wherein R
1 is independently selected from a C
2-C
18 hydrocarbon, an aryl group containing C
6-C
24 hydrocarbon, and a heteroarylgroup containing C
6-C
24 hydrocarbon; and wherein R
2 and R
7 are independently selected from a C
1-C
18 hydrocarbon, an arylgroup containing C
6-C
24 hydrocarbon, and a heteroarylgroup containing C
6-C
24 hydrocarbon; and in which G
2-G
9 are independently selected from hydrogen, halogen, R
3, OR
3, NHR
3, and NR
4R
3, wherein R
3 and R
4 are independently selected from an C
1-C
18 hydrocarbon, an arylgroup containing C
6-C
24 hydrocarbon, and an heteroarylgroup containing C
6-C
24 hydrocarbon, and where applicable, when one or more of G
2-G
9 are independently selected from R
3, OR
3, NHR
3, and NR
4R
3, wherein R
3=Y, with D, E, I, L and M independently being selected from hydrogen, halogen, R
5, OR
5, NHR
5, and NR
6R
5, wherein R
5 and R
6 are independently selected from an C
1-C
18 hydrocarbon, an arylgroup containing C
6-C
24 hydrocarbon, and an heteroarylgroup containing C
6-C
24 hydrocarbon. Here, hydrocarbon may relate to a substituted or unsubstituted, to a
saturated or unsaturated hydrocarbon, etc. etc. Further, such hydrocarbon may contain
cyclic or noncyclic groups, etc. The phrases "aryl group containing" or "heteroaryl
group containing" and similar phrases indicate that such hydrocarbon at least comprises
an aryl group or a heteroaryl group, respectively, but may in embodiments also comprise
two or more of such groups, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0103] Embodiments of the invention will now be described, by way of example only, with
reference to the accompanying schematic drawings in which corresponding reference
symbols indicate corresponding parts, and in which:
Figs. 1a-1f schematically depict some embodiments of the lighting device;
these drawings are not necessarily on scale;
Figs. 2a-2c show synthesis schemes and a number of organic luminescent materials made,
respectively;
Fig. 3 shows luminescence spectra (at RT) in ethyl acetate of those materials, also
in comparison with F083 (perylene);
Fig. 4a-4b depicts a number of organic luminescent materials for creating luminescence
spectra, as shown in Figs. 4c-4d; and
Fig. 5 depicts examples of further organic luminescent materials.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0104] Figure 1a schematically depicts a lighting device 1 with a light converter 100, which
in this embodiment at least comprises the organic luminescent material 140 according
to formula 1. The organic luminescent material 140 is in this embodiment embedded
in a (polymeric) matrix, such as PET. As can be seen, a remote version is shown, with
a non-zero distance d between the luminescent material (in the light converter 100)
and the light source(s), indicated with reference(s) 10. The lighting device 1 comprises
one or more light sources 10 which are configured to provide light source light 11,
especially blue and/or UV light. The lighting device 1 may comprise a plurality of
such light sources. When lighting device light, indicated with reference 2, of a white
nature is desired, it may be necessary to us an RGB concept, wherein the green and/or
yellow color, or at least part thereof, is provided by the green and/or yellow luminescent
material 140, and the blue and red light are provided by one or more of the light
source and a combination of the light source and another luminescent material, especially
the further luminescent material. The further luminescent material is indicated with
reference 130, and provides further luminescent material light 131.
[0105] The organic luminescent material 140 according to formula I provides upon excitation
by the light source light 11 and/or by emission of one or more other luminescent materials,
such as e.g. the further luminescent material light 131, organic luminescent material
light 141. Here, the light converter 100 is remote from the light source 10, and the
organic luminescent material, which is embedded in the light converter 100, is thus
also remote. The optional further luminescent material 130 can also be arranged remote,
see below, but is by way of example close to the light source 10, such as in a dome
and/or as layer on the LED die.
[0106] Just by way of example, one light source has been depicted without the further luminescent
material 130. However, in another embodiment, all light sources 10 may be configured
with at least further luminescent material 130. Also, by way of example three light
sources 10 have been depicted. However, more or less than three light sources may
be applied.
[0107] Note that the light source 10 may provide blue and/or UV light. The·further luminescent
material 130 may especially, upon excitation (by said light of the light source 10)
provide red light. Optionally, the further luminescent material 130 may also provide
green and/or yellow light.
[0108] Figure 1a, and other figures, schematically depict a device with a light chamber
170, with an enclosure 171, at least partly enclosing a cavity 172, which has a transmissive
part 173. In an embodiment, the transmissive part 173 comprises the light converter
100, or may especially consist of the light converter 100. The surface of the non-transmissive
part of the enclosure is indicated with reference 171. At least part of the surface
171 may comprise a reflector, such as a reflective coating.
[0109] The light converter 100 provides upon excitation light converter light 111, which
at least comprises organic luminescent material light 141 but may optionally comprise
other luminescence light as well (see below). The lighting device light, indicated
with reference 2, at least comprises light converter light 111 / organic luminescent
material light 141, but may optionally comprise one or more of the light source light
11, further luminescent material light 131, and light of other luminescent materials
(not depicted).
[0110] Figure 1b schematically depicts an embodiment wherein the light converter 100 may
comprise an upstream layer with further luminescent material 130. Optionally, this
may be a light converter comprising two layers comprising the same matrix, but comprising
different luminescent materials. The distance of the layer with further luminescent
material 130 to the light source is indicated with d1. This distance is in this embodiment
non-zero, in contrast to the embodiment schematically depicted in Figure 1a.
[0111] Figure 1c schematically depicts an embodiment wherein the light converter 100 comprises
the further luminescent material 140, e.g. in the form of quantum dots, and the organic
luminescent material 130 according to formula I. Both the organic luminescent material
140 and the further luminescent material 130 are in this embodiment embedded in the
(remote) light converter, i.e. embedded in the (polymeric) matrix of the light converter
100.
[0112] Figure 1d schematically depicts an embodiment wherein the transmissive part 173 comprises
at least two types of segments, with volumes over 0.25 cm
3, wherein the two types of segments comprise different weight ratios organic luminescent
material and further luminescent material. For instance, first segments only comprise
the organic luminescent material 140 as luminescent material and second segments only
comprises further luminescent material 130 as luminescent material. The organic luminescent
material 140 may also in this embodiment be embedded in a (polymeric) matrix, such
as PET. Likewise, also the further luminescent material 130 may be embedded in a (polymeric)
matrix, such as PET.
[0113] Figure 1e schematically depicts an embodiment wherein the enclosure 170 comprises
a transmissive diffuser 160 (as transmissive part 173) and the light converter is
applied to at least part of the non-transmissive part of the enclosure 171.
[0114] Figure 1f schematically depicts a reflective configuration. As mentioned above, the
organic luminescent material 140 and optionally the further luminescent material 140
may (both) be embedded in a (polymeric) matrix.
[0115] Combinations of embodiments may also be applied, like the segmented light converter
of Figure 1d in combination with or alternative to the light converter(s) shown in
the other drawings, such as e.g. 1a, 1b, 1e, 1f.
[0116] In Figures 1a-1d, the lighting device comprises a light transmissive window, which
comprises or consists of the matrix. Hence, the matrix may be applied as light transmissive
window. In Figures 1e-1f, a transmissive diffuser is used as transmissive window.
The transmissive window is used as an envelope, or as part of an envelope. Here, the
transmissive window envelopes at least part of the cavity 172. Note that the transmissive
window is not necessarily flat. The transmissive window, comprising in embodiments
the matrix, may also be curved, like in the embodiment of a TLED or in a retrofit
incandescent lamp (bulb).
EXAMPLES
[0117] By way of Example, a few syntheses are described below. Two synthesis schemes are
depicted in Figure 2a and 2b, respectively; a number of organic luminescent materials
made is schematically depicted in Figure 2c. Luminescence spectra of those materials,
also in comparison with F083 (prior art system), are depicted in Figure 3.
Synthesis of 2363:
1. 6-chloro-2-(2,6-diisopropylphenyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (2368).
[0118] A mixture of 4-chloronaphthalic anhydride (10 g, 43.0 mmol) and 2,6-diisopropylaniline
(16.2 mL, 86 mmol) in AcOH (300 mL) was refluxed overnight. The mixture was cooled
and poured into water. The precipitate was collected by filtration, washed with water
and dried under vacuum. Purification by column chromatography on SiO
2 (dichloromethane/heptane = 2:1) gave 7.5 g (44%) of pure compound
2368.
2. 4-(2-nitrophenoxy)-N-(2,6-diisopropylphenyl)-1,8-naphthalimide (2369).
[0119] A mixture of
2368 (7.5 g, 19.1 mmol), 2-nitrophenol (13.5 g, 34.4 mmol) and K
2CO
3 (5.3 g, 38.2 mmol) in NMP (300 mL) was stirred at 90°C under nitrogen overnight.
The mixture was cooled and poured into a mixture of AcOH (150 mL) and ice-water. After
5 minutes, 2 N HCl (200 mL) was added and the mixture was extracted with toluene (4x).
the combined organic layers were washed with water and brine, dried (Na
2SO
4), filtered and concentrated. Purification by column chromatography on SiO
2 (dichloromethane/heptane = 1/1 to 2:1) gave 6.7 g (71%) of pure compound
2369 as a white solid.
3. 4-(2-aminophenoxy)-N-(2,6-diisopropylphenyl)-1,8-naphthalimide (2370).
[0120] A solution of compound
2369 (5.7 g, 11.5 mmol) in a mixture of THF (60 mL) and MeOH (50 mL) under nitrogen atmosphere
was warmed to get a clear solution. The mixture was then cooled to room temperature
and 10% Pd/C (2 g) was added. The mixture was stirred 2h at room temperature under
hydrogen atmosphere (balloon) then filtered over a pad of celite and concentrated.
Purification by column chromatography on SiO
2 (dichloromethane) gave 4.9 g (90%) of pure compound
2370 as a yellow solid.
4. 2-(2,6-diisopropylphenyl)-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (2363).
[0121] A solution of compound
2370 (5.1 g, 11.0 mmol) in AcOH (80 mL) was treated with hydrochloric acid (1.5 M, 21
mL) and sodium nitrite (3.0 g, 43.9 mmol in 20 mL water) at 0°C. After 60 minutes,
a solution of CuSO
4.5H
2O (11.24 g, 45.0 mmol) in water (130 mL) was added. The mixture was refluxed for another
0.5 h and then allowed to cool. The precipitated yellow solid was filtered, washed
with water and dried under vacuum. Purification by column chromatography on SiO
2 (dichloromethane/heptane = 1/1 to 2:1) gave 850 mg (17%) of pure compound
2363 as a yellow solid. M+H=448.1. λ
max (ethyl acetate)=421nm, ε=25500 and 444nm ε=21300. λ(em) (ethyl acetate) 460nm and
490nm.
Synthesis of 2389
1. 5,11-dibromo-2-(2,6-diisopropylphenyl)-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione
(2404)
[0122] Bromine (2.7 mL, 53.64 mmol) was added to a solution compound
2363 (2 g, 4.47 mmol) in CHCl
3 (160 mL) under nitrogen. The mixture was stirred at 60°C for 5h cooled to room temperature
and concentrated. The various brominates products were separated by column chromatography
(SiO
2, eluent: toluene dichloromethane 1/1 to 2/1). Compound
2404 (1.8 g, 66%) was obtained as a yellow solid.
2. 2-(2,6-diisopropylphenyl)-5-bromo-11-phenoxy-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (2405):
[0123] A mixture of
2404 (1.4 g, 2.31 mmol), phenol (1.2 g, 12.75 mmol) and K
2CO
3 (2.2 g, 15.92 mmol) in NMP (60 mL) was stirred at 90°C under nitrogen overnight.
Then, the contents of the flask were poured into a cold 20% acetic acid solution in
water. After 5 minutes, 2 N aqueous HCl was added and stirred for 10 minutes and the
precipitated solid was filtered, washed neutral with warm water and vacuum dried at
60°C. The residue was coated on silica gel and purified by column chromatography (SiO
2, eluent: dichloromethane/Heptane 1/1 to 2/1). Compound
2405 (1.1 g, 76%) was obtained as a yellow solid.
3. 2-(2,6-diisopropylphenyl)-11-phenoxy-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (2389):
[0124] To a clear solution of compound
2405 (600 mg, 0.97 mmol) in THF (80 mL) and MeOH (10 mL) under nitrogen was added 10%
Pd/C (100 mg) and the reaction was placed under hydrogen atmosphere with a balloon.
The mixture was stirred at 30°C overnight and then filtered over Celite. The crude
solid was purified by column chromatography (SiO
2, eluent: toluene/dichloromethane 3/2). Compound
2389 (540 mg, 98%) was obtained as a yellow solid. M+H=540.2. λ
max (ethyl acetate)=428nm, ε=19300 and 449nm, ε=18500. λ(em) (ethyl acetate) 479nm and
506nm.
Synthesis of 2-(2,6-diisopropylphenyl)-5,11-diphenyl-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (2401):
[0125] Compound
2404 (500 mg, 0.83 mmol), phenylboronic acid (810 mg, 6.64 mmol), Pd(PPh
3)
4 (40 mg, 0.03 mmol) and Na
2CO
3 (265 mg, 2.50 mmol) were added to a degassed mixture of EtOH (1 mL), benzene (15
mL) and water (2 mL) under nitrogen. The mixture was reacted at 80°C overnight. The
reaction was quenched by addition of water and extracted with dichloromethane (3 x).
the combined organic layer was washed with water, brine, dried (Na
2SO
4), filtered and concentrated under reduced pressure. The crude solid was purified
by column chromatography (SiO
2, eluent: DCM/heptane 2/1). Compound
2401 (490 mg, 98%) was obtained as a yellow solid. M+H=600.3. λ
max (ethyl acetate)=435nm, ε=17700 and 455nm, ε 15600. λ(em) (ethyl acetate) 489nm and
516nm.
Synthesis of 2-(2,6-diisopropylphenyl)-11-phenoxy-5-phenyl-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione (2402):
[0126] Compound
2405 (400 mg, 0.65 mmol), phenylboronic acid (396 mg, 3.25 mmol), Pd(PPh
3)
4 (40 mg, 0.03 mmol) and Na
2CO
3 (130 mg, 1.22 mmol) were added to a degassed mixture of EtOH (1 mL), benzene (15
mL) and water (2 mL) under nitrogen. The mixture was reacted at 80°C overnight under
nitrogen. The reaction was quenched by addition of water and extracted with dichloromethane
(3 x). the combined organic layer was washed with water, brine, dried (Na
2SO
4), filtered and concentrated under reduced pressure. The crude solid was purified
by column chromatography (SiO
2, eluent: dichloromethane/heptane 1/1 to 3/2). Compound
2402 (390 mg, 97%) was obtained as a yellow solid. M+H=616.0. λ
max (ethyl acetate)=436nm, ε=17500 and 457nm, ε=16700. λ(em) (ethyl acetate) 491nm and
521nm.
Synthesis of 2413:
1. 2-(2,6-diisopropylphenyl)-6-(4-methoxy-2-nitrophenoxy)-1H-benzo[de]isoquinoline-1,3(2H)-dione
(2468).
[0127] A mixture of
2368 (12.0 g, 30.62 mmol), 4-methoxy-2-nitrophenol (8.9 g, 52.86 mmol) and K
2CO
3 (8.1 g, 58.60 mmol) in N-methylpyrolidone (150 mL) was stirred at 90°C under nitrogen
overnight. The mixture was cooled and poured into a mixture of acetic acid and ice-water.
After 5 minutes, 2 N HCl was added and the precipitate was collected by filtration,
washed with water and with methanol (removed excess of phenol) and dried under vacuum
to give compound
2468 (14g, 87 % yield) as a solid.
2. 4-(4-Methoxy-2-aminophenoxy)-N-(2,6-diisopropylphenyl)-1,8-naphthalimide 2469.
[0128] To a solution of compound
2468 (14.0 g, 28.31 mmol) in a mixture of THF (130 mL) and methanol (60 mL) under nitrogen
atmosphere was added 10% Pd/C (3 g). The mixture was stirred overnight at room temperature
under hydrogen atmosphere (balloon) then filtered over a pad of celite and concentrated.
To give compound
2469 (14 g, quantitative yield) as a ellow solid.
3. 2-(2,6-diisopropylphenyl)-9-methoxy-1H-xantheno[2,1,9-def]isoquinotine-1,3(2H)-dione 7 (2412).
[0129] A nitrosylsulfuric acid solution (40 wt. % nitric acid in sulphuric acid, 5.8 mL,
33.96 mmol) was added dropwise to a solution of compound
2469 (14.0 g, 28.3 mmol) in a mixture of acetic acid (100 mL) and propionic acid (30 mL)
at 0-5 °C. After 1h, the diazonium liquor was added portionwise to a boiling solution
of hydrated copper (II) sulphate (28.3 g, 113.2 mmol) in water (250 mL) and acetic
acid (16 mL). After the addition was complete, the liquor was boiled for lh, cooled,
diluted with water and the precipitated yellow solid was filtered, washed with water
and dried under vacuum. Purification by column chromatography on SiO
2 (dichloromethane/heptane = 1/1 to 2:1) gave compound
2412 (1.3 g, 9.6 %) as a yellow solid.
4. 2-(2,6-diisopropylphenyl)-9-hydroxy-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione 2470.
[0130] A solution of BBr
3 (1M in dichloromethane, 2.6 mL, 2.60 mmol) was added to a solution of compound
2412 (350 mg, 0.72 mmol) in dichloromethane (35 mL) at 0 °C under nitrogen. The mixture
was stirred at 40 °C overnight, cooled to 0 °C and a solution of NaHCO
3 was added. The mixture was extracted with dichloromethane (1x) and then with ethyl
acetate (3x) and the combined organic layers were washed with water and brine, dried
(Na
2SO
4), filtered and concentrated. Purification by column chromatography on SiO
2 (dichloromethane/methanol = 60/1 to 40/1) gave pure compound 2470 (284 mg, 84% yield)
as a yellow solid.
5. 2-(2,6-diisopropylphenyl)-9-phenoxy-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione 2413.
[0131] Potassium t-butoxide (91 mg, 0.81 mmol) was added to a solution of compound
2470 (342 mg, 0.74 mmol) in THF (50 mL) at 0 °C under nitrogen and the reaction was stirred
at this temperature for 15 minutes. diphenyliodonium trifluoromethanesulfonate (473
mg, 1.10 mmol) was added in one portion and the cold bath was removed. The mixture
was stirred at 40 °C for 1h then cooled to 0 °C, diluted with dichloromethane and
water was added. The organic phase was separated and the water phase was extracted
with ethyl acetate (2x). The combined organic phases were washed with brine, dried
(Na
2SO
4), filtered and concentrated. Purification by column chromatography on SiO
2 (dichloromethane/heptane = 2/1 to 4/1) gave pure compound
2413 (295 mg, 73% yield) as a yellow solid. M+H=540.2. λ
max (ethyl acetate)=429nm, ε=24800 and 452nm, ε=22100. λ(em) (ethyl acetate) 473nm and
501nm.
Synthesis of 2-(2,6-diisopropylphenyl)-5,11-diphenoxy-1H-xantheno[2,1,9-def]isoquinoline-1,3(2H)-dione
(2436):
[0132] A mixture
of 2404 (2.0 g, 3.3 mmol), phenol (10.0 g, 16.5 mmol) and Cs
2CO
3 (6.4 g, 19.8 mmol) in degased 1,4-dioxane (1560 mL) was stirred at 90°C under nitrogen
for 1h. Then, a mixture of Cu(I)I (314 mg, 1.65 mmol) and N,N-dimethylglycine (510
mg, 495 mmol) in 1,4-dioxane (4 mL) was added and the reaction mixture was stirred
at 90°C under nitrogen overnight. The mixture was cooled to room temperature and the
solvent removed under reduced pressure. The residue was dissolved in dichloromethane
and SiO
2 was added. The dichloromethane was removed under reduced pressure and the product
coated on silica was poured on top of a column chromatography for purification (SiO
2, eluent: dichloromethane/heptane 1/1). The compound was washed with hot heptane in
a glass filter an dried under vacuum. Compound
2436 (1.0 g, 48%) was obtained as a yellow solid. M+H=632.2. λ
max (ethyl acetate) 437nm, ε=19300 and 450nm, ε=19000. λ(em) (ethyl acetate) 499nm.
[0133] We tested the lifetime of various molecule in a PET (polyethylene terephthalate)
film by measuring the lifetime under illumination with blue light at 0.5-7 W/cm
2 at 60 °C. The concentration and the thickness of the layers were set so that the
transmission of blue light was 90%. All dyes in the PET film showed a PLQE (photoluminescent
quantum efficiency) between 0.92 and 0.96.
[0134] The lifetime is determined as 10% reduction extrapolated to the conditions for a
TLED (0.016 W/cm
2 blue and a temperature of 60 °C in air) assuming a linear dependence on the flux
density. In the case of F083 a lifetime of about 100 hours was estimated while new
compound 2363 showed a lifetime of about 2500 hours. This means an increase in lifetime
of about 25 times. For new compound 2389 the lifetime is further increased with another
factor of about 5 to 12500 hours under the same conditions. For new compound 2401
the lifetime is even further increased with another factor of about 10 to 27000 hours
under the same conditions
[0135] Lifetime of organic yellow emitting molecules in a PET matrix (in hours at which
10% has bleached at an exposure of 0.016 W/cm
2 blue and a temperature of 60 °C in air)
| F083 |
F170 |
Solvent yellow 98 |
2363 |
2389 |
2401 |
2402 |
2413 |
2436 |
| 50-200 |
150-400 |
400-650 |
2500-2800 |
10000-15000 |
27000 |
14000 |
6000 |
12000 |
Examples of white blends
Example 1
[0136] Emission of various organic molecules excited by blue LED can be combined to produce
white light. Herein, the emission from the molecules depicted in Figures 4a (material
2389, see Figure 2b) and 4b (N,N'-Bis(2,6-diisopropylphenyl)-1,7-di(2,6-diisopropylphenoxy)perylene-3,4:9,10-tetracarboxdiimide;
Cas nr. 919488-78-1), were combined with blue light to obtain white light with a spectrum shown in Figure
4c. Such a white light can be produced showing the following values shown in the table
below.
Example 2
[0137] In this example the emission from the molecules depicted in Figures 4a and 4b were
combined with blue light and also with emission from a inorganic phosphor thiogalate
(SrGa
2S
4:Eu
2+) to obtain white light with a spectrum shown in Figure 4d, and with values as shown
in the table below.
| |
Conversion efficiency (Lm/W optical blue) |
CCT |
CRI |
R9 |
| Example 1 |
243 |
4015 |
81 |
63 |
| Example 2 |
265 |
4016 |
86 |
22 |
[0138] Further examples of organic·luminescent materials according to formula I are depicted
in Figure 5. Herein, X may relate to a C-C bond or to an oxygen, i.e. an ether bond.
By way of Example, one or more of G
2 and G
3 comprise groups which include ether groups or which groups are fluorinated with one
or more fluor substituents, or G
2 and/or G
3 comprise Y groups, with one or more of D, E, I, L and M comprising alkyl groups which
include ether groups or which groups are fluorinated with one or more fluor substituents.
The organic molecules depicted in Figure 5 are amongst others provided as examples.
Other examples, with other groups or groups located elsewhere may also be possible.